Our new home came equipped with a Rinnai tankless water heater that runs on natural gas. It works quite efficiently, quietly and incredibly well. They do not require too much maintenance but do not neglect to flush out the system at least once a year - a must do if you have one. That is a somewhat straight forward job requiring the Calci-free or equivalent cleaning agent, a pump, two washing machine hoses, a 1/2" wrench and the knowledge to do it.

I have been servicing them in our community for a few years now (all the same units) and have gone on two calls in the last month that showed code 11 and code 12 on the read out. That means the furnace is either not lighting or not staying lit. There could be a bunch of reasons for this however the most common are three. #1, a dirty spark ignitor. That is easily cleaned with a piece of scotch-brite (no file or tools). I have found that only a minimal corrosion could and sometimes does cause a stoppage. #2 are dirty flame rods which can also be cleaned with the scotch-brite as well. #3 is a clogged burner hole which involves taking the entire burner unit out and cleaning it. Sometimes you get a spider inside the unit and simply clogs it up with his web. I have successfully done this a few times but WARNING, this job is not for most people here unless you are a professional or trained on Rinnai units. There are a whole lot of things to be careful with and lots of screws and parts to remove and remember how to replace. My neighbors down the street both begged me to take a crack at it because they could not get a Rinnai trained repair guy here anytime soon and taking cold showers was not their idea of fun. I gave them both my "disclaimer speech" and was able to help them out. Thankfully in both cases I was able to repair the units quickly. The units here are still under the 10 year warranty however the warranty will not cover lack of routine maintenance.

Again, if you own one of these units, don't neglect flushing them out yearly and do not forget to clean the small screw-out filter underneath the unit. Doing so will greatly extend the life of the heater. If you do not want to get involved in this job (most don't - I get that), call a professional and have him do it - but please do not neglect to service them! I can't tell you how many people here don't even know they require yearly servicing! As it usually goes, problems usually occur when you have a house full of guests over on a Holiday or something - not fun. Many stoppages can be completely avoided with simple routine maintenance.

Years back I went to a Rinnai training/sales meeting at the local Johnstone Supply. Mainly so I could buy one myself instead of going through a plumber$$$. I never did get one, but they have all kinds of bells & whistles you can add, like temperature controls at the showers & sinks, etc., so you only need one valve at point of use instead of a mixing valve. One thing I would do is install the piping to make the maintenance easier. Depending on your water, you may want to flush the heat exchanger more often.
A short time after I went to the class one of the counter guys told me Rinnai wasn't honoring the 10-year warranty, claiming lack of maintenance.
I suppose that may have changed by now. Those are a great concept, though, especially if you're updating some things to sell the house.
Edit to add: I would also install one of those Cuno brand water filter with the good lime & scale, etc., cartridge, on the supply line.

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Waiting For The Sun.

NO MORE CAPS!

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I’m your Boogie Man, uh huh.

Chief38, you the man. I flush mine with white vinegar, thats what I was told to do by first owner, is the Calci-free better. Also wash out the little screen. But nothing else. Took a photo of your thread, so I can follow up. Thanks, Bob

That is exactly why I document each service with pictures of the circulator pump working and the dates of service. When I let people know that these manufacturer's give people a hard time with a warranty claim I also suggest they document their service in a similar fashion. I also saved the receipts from the Calci-free, pump, hoses, etc.

We already have a whole house water filtration system which does an excellent job in filtering out the bad stuff before the water hits the Rinnai unit. They do suggest that in the manual as well.

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Got a spasm in my neck so I took the liberty.

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Those heaters may not be the best thing in this city without a whole house filter. The water here is so hard here your first bills comes with a mining license.

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I considered getting a tankless heater some years ago, but as a result of the high installation expense and on the advice of a local plumber who did not like tankless, I abandoned the idea. I have never had any real reason to move away from a tank type heater. I just acidize my tank every five years or so to get rid of the accumulated scale and sediment, a very simple and cheap job. My present gas tank heater is almost 20 years old, and I acidized it last Summer. We have very high hardness water here in San Antonio.

They need to be descaled annually. Twice a year if you have a water softener. I work for one of the largest new home builders in the country.

The son's new home in San Antonio has a Rinnai. I'll pass this information along to him in case he missed reading the manual (and he probably did.)

I, too, was advised by a plumber that tankless heaters didn't do well with our very hard water. San Antonio water is pretty hard, but ours out here on the edge of the desert is MUCH worse - extreme levels of calcium salts and very high fluoride levels along with other dissolved minerals.

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Or something like that . . .

Thank you Sir! Would you be kind enough to PM me and advise me how to rotate pictures here on the Forum? On my computer they are in the correct orientation and I have tried to fix them on many Forum posts but have been unsuccessful. No matter if I rotate them on my computer or not they still revert back to the wrong orientation here. I would truly like to correct this and would be very appreciative! Thanks.

This is the first house I've owned that had a tankless hot water heater and I really like it! It's hung on the wall so you don't sacrifice any floor space and they supposedly last 20 years or so if properly maintained. They are also quiet, clean, easy to service and supply an endless flow of hot water. We have also taken showers in all 3 bathrooms simultaneously with no noticeable decrease of hot water. After owning one for 3+ years I would highly recommend them. We have natural gas here and that is the real key to making them so efficient.

I place my index finger on the picture bringing up a slew of options, then click on “save to pictures”. The photo appears in my “camera” icon and I edit it by using the crop feature to rotate it, and hit “done”. The new pic replaces the previous one.

Probably a better way but this works for me.



Mine is on the wall also. I see the other non Rinnai units on the floor usually with a metal barrier around it, to keep folks from running into theirs.


Coming up on 8 years since we moved, time flies.

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Thanks for the heads up...funny that the company who installed the unit has said nothing about this...

I'm on propane, forced hot water heat, and had a standoff tank vs a separate water heater... Average propane usage was 900 gallon for heat an hot water a year...

Have had the unit now for probably 6-8 years at least and the usage has gone down to 550 gallons a year.

Probably have not had any issues with the unit as I'm on good quality city water...

Bob

I tried that along time ago and just tried it again now as you suggested. No dice - it does not stay rotated when I post it even though it does rotate in photos. My son will be here in a few weeks and he is a computer wiz so I will have him show me. Thanks for the effort! I've got to get to the bottom of this!

I have never seen a tankless hot water heater on the floor. All the ones here are wall mounted. When you flush the system don't forget to take pic's and write the date of service on the unit cover - it will help if submitting a warranty claim.

How does a tankless type perform when only a trickle of hot water is needed at an opposite end of the house? Is there a required minimum flow needed?

You will run cold for a few minutes, but once it gets going it won’t stop or run out. At least in my house that is.

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If you need a trickle of hot water you would have to turn it on a normal flow, let it run for a minute, then turn the flow down to a trickle. The water might get a little cooler if using it for a while. I am not aware of the exact flow required to activate the unit - but I might try that tomorrow for fun and report that here.

That said, even with a conventional hot water heater tank it would take a minute to run through the pipes and come out hot, however it would take a few seconds less and the water would probably remain hotter in that trickle.

There is no perfect system! Each different type has their pluses and minuses. Quite honestly, here in SWFL we typically don't use hot water all the time. The "cold" water here isn't nearly as cold is it is up North. The pipes here are not buried deep as they are up North since we do not have pipe freezing issues here, therefore the cold water is not really cold. To wash our hands, rinse something off, etc. we don't bother using hot water and it is not uncomfortable. Our hot water is mainly used for showers. Most of the dishes go into the dishwasher that uses hot water of course.

Conventional hot water tanks and or indirect hot water storage tanks (Super Stores) always keep the water hot and kick on when the temperature fall below a certain threshold that you set it on - even when not using the hot water. The Tankless system is on demand only so it does not come on unless you call for hot water. If you go away for a vacation, it never runs. From what I have seen from our natural gas bills, we use way way less natural gas because of that. The conventional tanks take up valuable space and are a major issue to replace. The tankless systems last longer (supposedly) and take up no floor space, mount on the wall and they are quite small to begin with. IMHO, they are also much easier to maintain than conventional tanks and are mounted at eye level so maintaining them is a snap!

Again, this house is our first home with this system and they do predict it to last about 20+ years when properly maintained. My hot water tanks and or storage tanks up North never lasted me more than 5-8 years so the tankless could last 3 times as long, take up no floor space, not be in the way at all, cost less to operate and supply endless hot water. Works for me! After having one for over 3 years now, I'd not ever install a conventional hot water tank or storage tank again.

OK - I tested that this morning. If the hot water is turned on to a trickle, the unit does not fire up. You have to turn it on at least to half flow for the unit to fire up. The only time I use a trickle is while shaving and while the hot water temp. drops slightly, it never gets cold.

When the hot water is turned off, the unit shuts down after only 4-5 seconds wasting almost no natural gas.